Dynamic Date within Beast Mode

I have a Beast Mode that is grouping transactions based on their date:

CASE WHEN OrderHeaderLocalDate >= '02/27/2024' THEN 'Since Changes CY'

  WHEN OrderHeaderLocalDate >= '08/01/2023' AND OrderHeaderLocalDate <= '02/26/2024' THEN 'Prior YTD CY'

  WHEN OrderHeaderLocalDate >= '02/27/2023' AND OrderHeaderLocalDate <= '04/08/2023' THEN 'Since Changes PY'

  WHEN OrderHeaderLocalDate >= '08/01/2022' AND OrderHeaderLocalDate <= '02/26/2023' THEN 'Prior YTD PY'

ELSE 'Not in Scope'

END

This works fine, and I was using another piece of data to figure out a Year to Date period for current and prior year so it was original 07/31/2023 in place of the 04/08/2023, however I have since found the the YTD flag that exists within the data already works in a different way to what I expected, so is including a few more days than I want.

I've tried various iterations of changing the 04/08/2023 (08/04/2023 in UK) to be dynamic and within the beast mode I was getting a validated code, but when using in a visualization no results.

I have tried finding the Max date within OrderHeaderLocalDate - 366 days (leap year), this worked within a beast mode and then visualisation, but within the case seems to be a no go.

Is anyone able to help with a solution to change 04/08/2023 to what is effectively the most recent order within the dataset minus 1 year within the case statement? This means that each day when the dataset is updated with the latest transactions I won't have to make an amend every day!

I'm sure there is a simple solution I am making massively more complicated than it needs to be!

Thanks!